Identifying acute myocardial infractions early on and treating them promptly significantly improves the clinical outcomes. Studies have shown that the most irreversible myocardial damage occurs in the first 30 to 90 minutes of coronary occlusion. It has been demonstrated that providing reperfusion therapy within two hours of occlusion has the greatest chance to save the myocardium. Also, evidence exists that even in cases of the most severe type of myocardial infarction (MI) called ST elevation MI (STEMI), rapid restoration of blood supply after onset of symptoms is a key factor in determining the short and long term outcomes. Therefore, it is very clear that early arrival at the hospital for prompt diagnosis and treatment is the key to increasing the odds of a better outcome.
Despite wide-spread public campaigns and education on this matter, the average time for a patient to reach the hospital from the onset of the symptoms is more than three hours in urban areas and can be longer than 20 hours in rural areas. The cause of the delay is mostly due to the ignoring or the misconception of the symptoms experienced by the patient and their confusion with their attributes. Most of the heart attacks are silent and cause little to no pain. In case of diabetic patients, it is even worse because they do not feel the attack at all. FIG. 1 is a schematic representation that captures the overall view of the American Heart Association regarding the delay in symptom recognition and reaching the hospital as the leading causes of death in coronary heart diseases (both sudden cardiac deaths and heart attacks). This scenario clearly states the need for a device that can warn the patient when they go through the myocardial infarction and prompts them to seek immediate attention. Such a device can save lives and can also save billions of dollars in costly after care treatment.
Taking a look at the current state of the art in surveillance of coronary heart diseases, the options available are (i) 12 lead ECG machines, which are not portable and mostly available in hospital settings; (ii) Holter machines, which have no real time prediction capability to forewarn an impending heart attack; (iii) Contemporary monitoring solutions that can detect only simple arrhythmias by measuring RR intervals and cannot detect impending heart attacks because lethal arrhythmias are presented after the start of the attack; and (iv) implantable devices that can monitor ST-elevation or depression and provide warning. The drawback of the implantable device is that it requires surgery and caters only to the high risk population.
Clearly none of the options set forth in the above list can satisfy the current unmet need, i.e., an accurate early warning system for heart attack and sudden cardiac death. Such an early warning system should also be capable of being used easily and by a larger segment of the public. The claimed invention is directed to the development of such a method and device.